C语言之数值交换

关于数值交换的几种方法：

一、引用中间变量

1、直接利用中间变量

#include <stdio.h>

int main(){

int a = 10;

int b = 20;

int c;

//交换前

printf(" Before switch:a = %d,b = %d\n",a,b);

//交换

c = a;

a = b;

b = c;

//交换后

printf("After switch:a = %d,b = %d\n",a,b);

return 0;

}

2、通过指针实现

#include <stdio.h>

void change(int *,int *);

int main(){

int a = 10;

int b = 20;

//交换前

printf(" Before switch:a = %d,b = %d\n",a,b);

//交换

change(&a,&b);

//交换后

printf("After switch:a = %d,b = %d\n",a,b);

return 0;

}

void change( int * p1 ,int * p2){

int c = *p1;

*p1 = *p2;

*p2 = c;

}

二、不引用中间变量

1、利用加法

      //此种方法可能会溢出；

#include <stdio.h>

int main(){

int a = 10;

int b = 20；

//交换前

printf(" Before switch:a = %d,b = %d\n",a,b);

//交换

a = a + b;

b = a - b;

a = a - b;

//交换后

printf("After switch:a = %d,b = %d\n",a,b);

return 0;

}

2、通过运算符^

#include <stdio.h>

int main(){

int a = 10;

int b = 20;

//交换前

printf(" Before switch:a = %d,b = %d\n",a,b);

//交换

a = a^b;

b = a^b;

a = a^b;

//交换后

printf("After switch:a = %d,b = %d\n",a,b);

return 0;

}